Insulation panel and fastener assembly



April 8, 1969 w. M. CHARMAN, JR., ET AL INSULATION PANEL AND FASTENERASSEMBLY Original File'd Oct. 31, 1966 I warm/10mm JO/IA/ sues: 3W

Armwivs INSULATION PANEL AND FASTENER ASSEMBLY Walter M. Charman, In,Shaker Heights, and John Eugene Jackson, Beachwood, Ohio, assignors toOglebay Norton Company, Cleveland, Ohio, a corporation of DelawareOriginal application Oct. 31, 1966, Ser. No. 590,808, now Patent No.3,372,524, dated Mar. 12, 1968. Divided and this application Feb. 27,1968, Ser. No. 708,564

Int. Cl. E04f 13/08; E04b 1/74; E04c 1/40 U.S. Cl. 52127 10 ClaimsABSTRACT OF THE DISCLOSURE This invention relates to a preassembledinsulation panel and fastener assembly for installation in an ingotmold.

This application is a divisional application of our copendingapplication Ser. No. 590,808, filed Oct. 31, 1966, now Patent No.3,372,524.

It has been the practice for some time to attach heat insulation panelsat the inside of the upper end of an iron ingot mold to provide a heatinsulating liner or hot top for the purpose of maintaining a reservoirof hot metal on top of the ingot during solidification, as is well knownin the art. Such insulation panels must be so firmly attached to theingot mold that they are maintained in proper position during movementof the mold, usually by rail, from the location where the heatinsulation panels are installed to the pouring pit. During the pouringoperation, the heat insulation panels must not loosen and float out oftheir position against the mold wall, which they tend to do because ofthe great difference in specific gravity between the panels and themolten steel. Such floating out of a panel destroys its function as ahot top and usually results in a piped ingot and loss of yield. It isalso important to prevent any appreciable amount of steel from rising upand solidifying between the heat insulation panels and the mold wallsduring the pouring operation. Such steel fins between the panels andmold walls may tend to prevent the escape of any gases generated by theburning of any organic materials or binders in the panels, causingboiling and displacement of the panels during pouring. Such fins alsocause difliculties during the later rolling of the ingot, by foldingback and rolling into and marking the surface of the good product in theingot.

Prior to the present invention, the heat insulation panels have beenattached to ingot mold walls by using a fastening tool to drive steelfastening pins through the panel and into the iron mold wall. Inaccordance with this practice, the fastening tool is a gun-like,explosive powderactuated, impact tool having a recess in its muzzle endinto which the user may insert by hand a fastener pin with a washerthereon. The barrel of the tool contains a slidable piston for drivingthe fastener pin through the heat insulation panel and into the moldwall. A powder charge cap in the tool is exploded, by means of aspringactuated firing pin, and such explosion drives the piston forwardin the barrel to force the fastener pin through the heat insulationpanel and into the mold wall. With one type of tool commonly used, amechanical blow on a plunger, which in turn strikes and explodes thepowder charge, is provided by a hammer which is swung by the operator.This requires that there be enough clearance across the inside of theingot mold for the operator to do this conveniently. Also, it requires afirm backup for the heat insulation panel so that, when the impact blow3,436,883 Patented Apr. 8, 1969 is struck with the hammer, the energy ofthe blow is not cushioned by movement of the panel toward the mold wall.If this occurs, the explosive charge cap may not fire. Also, sometimesthe hammer blow may break the heat insulation panel, or if the panel isnot held firmly against the mold wall the fastener pin and its washermay be driven too far into the panel and may produce a hole in the panelthe diameter of the washer, with consequent loss of holding force of thepanel against the mold wall.

Safety is another problem with this prior practice. Since the fastenerpin must be inserted manually into the impact gun before the latter ispositioned down inside the mold for use, there is a possibility that theimpact gun can be fired accidentally before it is so positioned. As asafety precaution, in the prior practice the impact gun is provided witha safety nose on its muzzle end which prevents the gun from being fireduntil the nose is retracted by forcing it against the panel in place atthe inside of the ingot mold. Since considerable force must be exertedto retract this safety nose, this is usually an awkward operationbecause the workman must perform it while leaning down from the top ofthe ingot mold. Powder-actuated impact guns require a licensed operatorin some states for safety reasons, and this limits their use for thepurpose intended.

Another disadvantage of the prior practice is that the work is usuallydone with the operator standing on top of the ingot mold, and he mustdrive the fastener pins into the heat insulation panel which is belowthe top of the mold on which he is standing. This practice is slow andlaborious, since ten or more fastener pins must be driven on the largermold sizes, and each shot requires that the breech of the impact gun beopened, a new powder cap installed, a fastener pin and washer installedand held in the barrel of the gun, the gun held against the panel, andthe gun be discharged by striking a hammer blow. Before shooting starts,mold clips or clamps usually must be installed to hold the panelsagainst the mold wall.

The present invention is directed to improving the safety and the easeand speed with which such heat insulation panels can be installed in aningot mold.

In accordance with the present invention, the heat insulation panel andas many fastener pins as are needed for it are pre-assembled as aunitary structure, with the fastener pins preset to a predetermineddepth in the panel and having their head ends projecting from one sideof the panel. The pre-setting of the fastener pins in the paneleliminates the need for their insertion by the operator manually intothe fastening gun. Instead, the operator simply telescopes the muzzle ofthe gun over the projecting head end of the fastener pin and thispositions the latter for an impact blow by the piston when the gun isfired. This greatly improves the ease and speed with which the fastenerpins can be driven into the mold wall because all the operator isrequired to do, once the panels are hung in the ingot mold, is to reloadthe powder cap after each shot, seek out the end of the fastening pinwhich projects from the heat insulation panel, telescope the gun muzzleover this pin, and operate the firing mechanism of the gun to drive thepin home into the mold wall. Preferably, in accordance with the presentinvention the gun is fired by means of a remote firing mechanism whichthe operator can actuate While standing upright on top of the mold.Also, accidental firing of the impact gun produces no safety hazardbecause the fastener pin is not present in the gun except when the gunis positioned to drive the pin into the mold wall.

It is an object of this invention to provide a novel preassembled,unitary heat insulation panel and fastener assembly for attachment tothe inside of an ingot mold.

Another object of this invention is to assure that by presetting thefastener pin in the heat insulation panel perpendicular to the face ofthe ingot mold the fastener pin point will penetrate the surface of theingot mold at right angles to the face of the ingot mold, therebyeliminating hazardous fishhooking of the fastener pin with subsequentloss of holding power.

Further objects and advantages of the present invena tion will beapparent from the following detailed description with reference to theaccompanying drawing, in which:

FIG. 1 is a fragmentary exploded perspective view showing the heatinsulation panel and one of the fastener pin assemblies therefor inaccordance with a first embodiment of the present invention;

FIG. 2 is a horizontal section through the heat insulation panel withthe FIG. 1 fastener pin preset therein;

FIG. 3 is a view similar to FIG. 2 and showing the heat insulation panelfastened to the inside of an ingot mold by driving the fastener pin fromthe preset phantom line position to the final full-line position;

FIG. 4 is a perspective view showing a workman installing heatinsulation panels in an ingot mold in accordancewith the presentinvention;

FIG. 5 is an enlarged elevational view of the pointed end of thefastener pin in the present invention; and

FIG. 6 is a perspective view of a second embodiment of a fastener pinassembly in accordance with the present invention.

Referring to FIGS. 1 and 2, in accordance with a first embodiment of thepresent invention, before being installed in an ingot mold the usualheat insulation panel 10 is provided with preferably as manypreassembled fastener pin assemblies 11 as are necessary for fasteningit securely to the inside of the mold.

In one practical embodiment, the insulation panel 10 is predominantlysilica sand with approximately equal parts of fibrous material, such asasbestos, and a suitable binder, such as a phenolic resin.

The fastener pin assembly 11 in this particular embodiment comprises arelatively broad area, flat, rectangular impact plate 12, which is heldflush against the inside face 13 of the insulation panel 10 by staples14 driven through the plate. Alternatively, the impact plate 12 may beattached to the insulation panel 10 by integral tangs on the plate whichare driven into the panel, or by any other suitable attachment memberswhich will be effective to hold the plate securely against the panel, asshown, or it may be held by the fastener pin itself, the pin beingdescribed hereinafter. Alternatively, the impact plate 12 may be moldedinto the panel as the panel is formed, or the impact plate may be gluedto the panel.

The impact plate 12 has a central opening 15 which is surounded by fourtabs, including a pair of fiat, opposed tabs 16, 17, which are coplanarwith the plate proper, and a pair of opposed, inwardly-bent tabs 13, 19.As best seen in FIG. 2, the bent-in tabs 18 and 19 are formed integralwith the plate 12 and they extend into the thickness of the insulationpanel 19 at opposite acute angles of approximately 20 to the plane ofplate. These bent-in tabs terminate in confronting arcuate edge portions211 and 21 which are offset inwardly from the plane of the impact plateand which partially define the plate opening 15. The tabs 16 and 17,which are coplanar with the plate proper, also terminate in confrontingarcuate edges 22 and 23 (FIG. 1) which define the remainder of theoutline of the plate opening 15.

The fastener pin assembly 11 also includes a fastening pin 24 having anelongated cylindrical shank 25 which carries a flat metal washer 26. Thewasher 26 has a tight interference frictional fit on the fastener pin.The fastener pin has a pointed inner end 27 and an enlarged head 28 onits outer end.

As best seen in FIG. 2, in accordance with the preferred form of thepresent invention the fastener pin assembly is pro-assembled with theheat insulation panel 10 to provide a unitary structure by firstattaching the impact plate 12 to the inside face 13 of the panel by thestaples 14 or other methods previously suggested and then driving thepointed end of the fastener pin through the opening 15 in the plate 12and into the panel 10 until the Washer 26 abuts against the impact plate12. Preferably this is done without disturbing the original position ofthe washer 26 on the fastener pin, so that this position of the washeraccurately predetermines the depth of penetration of the fastener pininto the panel 10 during this preassembly. As shown in FIG. 2, thefastener pin preferably penetrates most, but not all, of the way throughthe thickness of the panel 10. The cylindrical shank 25 of the fastenerpin 24 is gripped frictionally by the arcuate edges 20, 21, 22 and 23 ofthe integral tabs 16-19 on the impact plate, so that the fastener pincannot become dislodged from the panel 10 during its shipment to theingot mold or while it is being handled.

Referring to FIG. 3, the heat insultion panel 10 is to be positionedagainst the flat inside face 30 of an upstanding wall 31 of an ingotmold and then fastened to this wall by driving the fastener pin 24 fromthe preset phantom line position in FIG. 3, in which it projects fromthe panel, to the final full-line position of FIG. 3, in which itpenetrates completely through the panel 10 and into the ingot mold wall31. In this final position the fastener pin head 28 may abut against thewasher 26, as shown in FIG. 3, or it may be spaced outwardly from thewasher. The fastener pin is driven home by applying an impact blow onthe head end of the fastener pin of sufficient force to drive thefastener pin shank through the frictionally-held washer 26 and throughthe opening 15 in the impact plate until the pointed end 27 of thefastener pin has passed completely through the remaining thickness ofthe heat insulation panel 10 and into the ingot mold wall 31 to therequired depth which will insure secure attachment. The impact plate 12distributes the shock of the impact blow over a relatively broad area ofthe insulation panel to avoid breaking the latter or driving the washerthrough the panel, which otherwise would tend to happen due to thephysical characteristics of the panel 10.

The depth to which the fastener pin 24 is preset into the insulationpanel 10 preferably is chosen so that, when the fastener pin is driveninto the ingot mold wall, it will penetrate into the latter a sufficientdepth to provide a secure fastening, even if there is as much as inch to/2 inch of steel scrap or slag on the ingot mold wall behind the panel.

Referring to FIG. 4, such attachment of the insulation panel 10 to theingot mold is done by the remotelyoperated firing of an explosivepowder-actuated impact fastener tool G. As shown in this figure, theinsulation panels 10 may be suspended in position against the inside ofthe respective Walls of the ingot mold be means of wire hangers 35 whichare looped over respective rigid bars 36 resting on top of the ingotmold or by other means, not shown. Each insulation panel 10 preferrablyhas the required number of fastener assemblies 11 preassembled in place,as already described in detail, with the head end of each fastener pinprojecting from the panel, as shown in phantom in FIG. 3.

The gun-like impact tool G preferably is of a known type having anexplosive powder charge cap for operating a piston which is slidablewithin the barrel of the gun. The muzzle of the gun barrel has a recessfor receiving the head end of the fastener pin, and when the powdercharge is fired the piston inside the gun barrel drives the fastener pincompletely through the insulation panel and into the mold wall. The toolG is provided with a trigger and, in accordance with the present method,a remote control firing element, including a flexible cable C, isconnected to the trigger. This remote control ele ment extends from thegun above the top of the ingot mold. The trigger of the impact tool isoperated by an upward pull on the cable C, which may be done by amanually-operated remote control firing element, not shown. As shown inFIG. 4, the tool G is attached to the lower end of a rigid handle H. Theworkman holds the upper end of this handle H and operates the remotecontrol firing element, including cable C, while standing erect on topof the mold or on an adjacent platform.

In the use of this powder-actuated piston-type impact tool, theoperator, holding the handle H, telescopes the gun muzzle over theoutwardly-projecting head end of the fastener pin 24 which is preset inthe insulation panel, so that the fastener pin is now positioned to beengaged by the piston in the gun barrel. When an upward pull is exertedon the control cable C, such as by means of a remote control firingmechanism, this operates the trigger to fire the tool to drive thefastener pin into the mold wall. This may be done while the operator isstanding erect on top of the mold as shown in FIG. 4, or on an adjacentplatform, not shown. There is no necessity for the operator to insertthe fastener pin manually into the tool before positioning the toolagainst the heat insulation panel, as in the prior practice, because thefastener pin is already in place in the panel 10, and between successivefirings the operator need only replace the explosive charge cap in thetool. Also, the powder-actuated piston-type impact tool need not havethe aforementioned retractable safety nose to prevent accidental firingof the tool. Consequently, the time between successive firings of thetool is greatly reduced and there is no safety hazard because thefastener pin is never in place in the tool except when the tool istelescoped over the fastener pin which is preset in the panel 10.

Referring to FIG. 5, in accordance with the preferred embodiment of thepresent invention the fastener pin 24 has a novel construction whichmore effectively prevents it from being dislodged from the mold wall 31after it is driven in, as shown in the full-line position of FIG. 3.Referring to FIG. 5, the pointed end 27 of the fastener pin has arounded and tapered configuration, commonly referred to as an ogiveshape. This rounded and tapered end of the fastener pin has a curvaturesuch that at its juncture with the shank 25 a distinct corner 39 isformed, as shown somewhat exaggerated in FIG. 5. This is in contrast tothe prior practice of providing a smoothly merging or tangentialblending of the ogive-shaped end of the fastener pin with the shank ofthe fastener pin by having the curvature of the ogive, where it isjoined to the shank, such that there is no corner or other discontinuitybetween them, as indicated by the phantom lines 25' in FIG. 5. In otherwords, in the present fastener pin the tangent of the curve of the ogivetip at its intersection with the shank of the fastener pin does notextend along the shank as it would if the ogive blended into the shankof the pin, but rather at a diverging angle with respect to the shank,proceeding away from the tip.

It has been found that the provision of this corner or discontinuity 39between the uniform diameter shank 25 and the progressively decreasingdiameter ogive-shaped tip 27 of the fastener pin enables it to have anunexpectedly more secure embedding in the cast iron mold wall whendriven into the latter because cast iron has low resiliency, and whendisplaced by the entrance of the fastener pin point, grips more securelyon shank 25, particularly at the distinct corner 39, than if the castiron were displaced still more by a tip which merges or blends smoothlywith the shank, as shown at 25' in FIG. 5

FIG. 6 shows an alternative embodiment of the present fastener whichconsists of a fastener pin 24', preferably having a pointed endidentical to the fastener pin already described, and an impact plate 40.The shank of this pin is knurled at 46 just ahead of the head 28. Theplate 40 is a nonrectangular parallelogram in outline, having a pair ofshort opposite side edges 41, 42 and a pair of longer opposite sideedges 43, 44 joining them. The edges 41 and 44 extend at substantialyless than to one another and they form a sharp corner which may bestraddled by a staple 14', shown in phantom in FIG. 6 for attaching theimpact plate to the heat insulation panel. The opposite corner of thisplate, at the intersection of its remaining side edges 42 and 43, may besimilarly straddled by such a staple.

The impact plate 40 has a circular opening 45. This opening receives theshank of the fastener pin 24' with a tight frictional fit.

The impact plate 40 and pin 24' may be assembled together as shown inFIG. 6, with the pointed end of the fastener pin projecting past theplate 40 by an amount corresponding to the desired depth of its partialpenetration through the insulation panel. The fastener pin may be driveninto the insulation panel until the plate 40 abuts against the face ofthe panel, and then the plate is stapled to the panel to provide thepreassembled unitary structure of the panel and the fastener assembly.The knurled surface 46 on the shank of the fastener pin will be securelygripped by the frictional fit with the impact plate 40 at the lattersopening 45 to insure that the impact plate cannot come loose from thefastener pin after the latter is driven into the side of the mold.

While certain presently-preferred embodiments of the presentpreassembled panel and fastener pin structure, as 'well as the preferredmethod of installing this panel and fastener pin structure in an ingotmold, have been described in detail with reference to the accompanying:drawing, it is to be understood that modifications which depart fromthese particular embodiments may be adopted without departing from thescope of the present invention, as defined in the appended claims.

What is claimed is:

1. A preassembled panel and fastener pin assembly for attachment to theinside of an ingot mold, said assembly comprising a heat insulationpanel, an impact plate on said insulation panel at one side thereof andhaving an opening, and a fastener pin element frictionally received insaid opening in the impact plate and having an inner end extending intothe panel and an outer end projecting beyond the plate at said one sideof the panel.

2. An assembly according to claim 1, wherein said fastener element is apin having a pointed end embedded in the panel at a predetermined depththerein.

3. An assembly according to claim 2 wherein said fas tener pin has asubstantially cylindrical shank portion projecting into the panel and arounded and tapering pointed end segment extending inward into the panelfrom said shank portion, said tapering pointed end segment having anontangential curvature adjacent its juncture with said shank portionsuch that a distinct corner is provided at said juncture.

4. An assembly according to claim 1, wherein said plate at said openinghas integral bent-in tabs which project into the panel and terminate inedge portions of said opening which are ofiset inwardly and which gripthe fastener pin frictionally to lock the fastener pin againstdisplacement out of the panel.

5. An assembly according to claim 4 and further comprising a fiat washerfrictionally gripping the fastener pin and abutting against the outsideof said impact plate.

6. An assembly according to claim 5, wherein said fastener pin has acylindrical shank portion projecting through said plate into the paneland an ogive-shaped inner end segment extending inward, nontangentially,from said shank portion to an end tip and forming a distinct corner withsaid shank portion at their juncture.

7. A preassembled panel and fastener pin assembly for attachment to theinside of an ingot mold, said assembly comprising a heat insulationpanel, an impact plate on said insulation panel at one side thereof andhaving an opening, and a fastener pin element extending through saidopening in the impact plate and having an inner end extending into thepanel and an outer end projecting beyond the plate at said one side ofthe panel, said fastener pin element being releasably held in saidopening in the impact plate and being displaceable With respect to theimpact plate by an impact blow on the outer end of the fastener pinelement in the direction of the panel for driving the fastener pinelement into the panel.

8. An assembly according to claim 7, wherein said fastener element is apin having a pointed end embedded in the panel at a predetermined depththerein.

9. An assembly according to claim 8, wherein said (fastener pin has asubstantially cylindrical shank portion projecting into the panel and arounded and tapering pointed end segment extending inward into the panelfrom said shank portion, said tapering pointed end segment having anontangential curvature adjacent its juncture with said shank portionsuch that a distinct corner is provided at said juncture.

10. An assembly according to claim 8 or 9, and further comprising a flatWasher holding the fastener pin and abutting against the outside of saidimpact plate.

References Cited UNITED STATES PATENTS 2,853,746 9/1958 Spencer et al52-479 3,147,832 9/1964 Saro 52-506 3,372,524 3/1968 Charman et a1 52747FOREIGN PATENTS 616,559 3/1961 Canada. 1,0783 67 5/ 1954 France.

793,933 4/ 1958 Great Britain.

ALFRED C. PERHAM, Primary Examiner.

. US. Cl. X.R. 52-173, 404, 512

